1. Field of the Invention
This invention relates generally to valving mechanisms for operation and timed relationships to another moving structure, such as reciprocating or rotating pumps, compressor heat engines, etc., and more particularly to a nutating valving arrangement in which one plate member moves in nutating relationship to at least one other static plate member such that openings defined through each of the plate members come into alignment for selected portions of the nominal cycle.
2. Description of the Prior Art
Numerous valving arrangements for timed operation relative to, for instance, a rotating shaft are known. For purposes of convenience, discussion of such arrangements with reference to a reciprocating piston device will be addressed.
Perhaps the most common timed valve mechanism is a poppet valve in which a tulip valve reciprocates in timed relationship to rotation of a shaft, usually by a cam shaft driven by an associated crank shaft. Though widely accepted, the poppet valve suffers several problems. A reciprocating motion with accompanying acceleration forces limits speed of operation and at high speed tends to induce wear of the valve and seat. Also, even when opened, the poppet valve obstructs to a substantial extent the opening and thus restricts flow.
Another simpler valving arrangement is that of a piston timed port in which a simple opening is defined, for instance, in a cylinder wall in communication with a port such that a reciprocating piston in the cylinder will open and close the port as a piston travels thereby. In addition to wear problems resulting from the rapidly moving piston, or more after piston rings, travelling over the opening, such arrangement is inappropriate for use in the ubiquitous four stroke Otto-cycle engine in that the timing of such device usually causes a valve to open on the upstroke of the piston to remain open through a complete downstroke and somewhat into the following upstroke. Thus, a valving device that opens at a fixed position in each stroke is clearly inappropriate and inflexible.
Rotary valves in which, in the common instance, a fixed cylinder having an opening defined therethrough is contained in or contains a rotating cylinder having a complementary opening therethrough such that as the rotating cylinder passes through an aligned arrangement between the opening therein and the fixed cylinder opening flow occurs, has certain apparent advantages. Reciprocating parts are avoided. However, because of the extensive travel between various portions of the valving mechanism, wear and accordingly sealing shortcomings have often developed when such rotary valves are used. In a related arrangement, a disc rotating adjacent in opening again involves substantial surface to surface wear as the disc rotates through each valve cycle.
An unusual valving mechanism is described in U.S. Pat. No. 4,325,331 issued April 20, 1982 to Frederick L. Erickson. As particularly well shown in FIGS. 30 through 32, a combination of edge surfaces of a reciprocating piston and orbiting piston are used to effect a variation of the above described piston timed port arrangement, such configurations clearly are restricted to timing rate, duration and/or location of the parts.
Numerous other valving arrangements have been proposed, but usually with the disadvantages or combinations of disadvantages discussed above resulting from reciprocating or rotary movement between the different valve components.